1.Isolation and identification of mosquito-borne viruses in Huachuan county and Huanan county, Heilongjiang province, China
Han CHEN ; Fengming LIU ; Liqin YU ; Fan LI ; Shihong FU ; Qikai YIN ; Qianqian CUI ; Ruichen WANG ; Kai NIE ; Mingjia BAO ; Huanyu WANG ; Songtao XU
Chinese Journal of Experimental and Clinical Virology 2025;39(2):182-188
Objective:To investigate the mosquito-borne viruses carried by mosquito specimens collected from Huachuan county and Huanan county in Heilongjiang province.Methods:Mosquito samples were collected locally in 2023 and processed in the laboratory. Homogenates of the mosquitoes were inoculated into cells for virus isolation, followed by molecular and bioinformatics analyses of the viral isolates.Results:In 2023, ten viral isolates were obtained from Anopheles sinensis specimens collected in Heilongjiang province, China. Among these isolates, one was identified as Culex flavivirus (CxFV), one as Menghai rhabdovirus (MRV), and eight as Nam Dinh virus (NDiV). The phylogenetic analysis showed that CxFV belongs to genotype I and is clustered with the strains isolated from Liaoning province in 2011 and Ningxia Hui autonomous Region in 2019 in the same evolutionary branch, with amino acid similarity ranging from 98.2% to 99.2% and nucleotide similarity ranging from 98.8% to 99.2%. The MRV strain belongs to the same evolutionary subclade as the strain detected in Guangdong, with both nucleotide and amino acid similarity of 98.0%. Eight NDiV isolates clustered with the South Korean isolates on the same evolutionary branch, forming an independent evolutionary sub-branch. The nucleotide similarity among these eight isolates ranged from 98.5% to 99.7%, while the amino acid similarity ranged from 98.1% to 99.7%. In comparison, when matched with other NDiV isolates from China, the nucleotide similarity of these eight isolates ranged from 94.1% to 97.8%, and the amino acid similarity ranged from 93.5% to 97.7%.Conclusions:This study represents the first isolation of CxFV, MRV, and NDiV in Heilongjiang province, China, and the findings provide fundamental data for the prevention and control of mosquito-borne viral diseases in this region.
2.Establishment of a nucleic acid detection method for varicella-zoster virus based on RAA-CRISPR/Cas12a
Ziyi LI ; Ruichen WANG ; Haoze LIU ; Tianzi ZHANG ; Tianxin SHI ; Qianqian CUI ; Qikai YIN ; Fan LI ; Kai NIE ; Shihong FU ; Huanyu WANG ; Canlei SONG ; Qiufang XU ; Songtao XU
Chinese Journal of Experimental and Clinical Virology 2025;39(2):242-249
Objective:To establish a method for the rapid detection of varicella-zoster virus (VZV) by recombinase-aid amplification (RAA) combined with Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas12a system.Methods:Clinical samples of suspected herpes zoster in Shandong province and Shanghai from 2023 to 2024 were collected, nucleic acids of positive samples were extracted, RAA-specific primers and crRNA (CRISPR RNA, crRNA) were designed for the conserved region of VZV, and the fluorescence intensity generated by Cas12a non-specific cleavage of single-stranded fluorescent probes was used to screen highly sensitive crRNAs and optimize the concentrations of crRNA, Cas12a and ssDNA probes. The sensitivity and reproducibility of the RAA-CRISPR/Cas12a detection method were evaluated by using synthesized plasmids and clinical samples, and the specificity of the method was evaluated by using other viral nucleic acids. The method was used to detect clinical samples by using the method and quantitative real-time PCR (qPCR) method, and the detection rate and consistency of the two method were compared.Results:The highly sensitive crRNA-4 was screened from the four crRNAs designed, and a VZV detection method for RAA-CRISPR/CAS12a based on fluorescence intensity measurement was established, which could be detected at 37℃ in 45 min, and the sensitivity of the detection could reach 10 copies/μL, a minimum clinical sample with a Ct value of 38.980 can be detected. It has high specificity and no cross-reactivity with Adenovirus 7, Herpes simplex virus type I, Herpes simplex virus type II, Coxsackieviruses A16, Cytomegalovirus, Epstein-Barr virus, Measles virus, Mumps virus, Enterovirus 71, Japanese encephalitis virus genotype 5. It has good stability, and can be successfully detected in low, medium and high concentrations of viral positive plasmids with good consistency. The detection rate of the clinically positive samples was 100%, which was completely consistent with the qPCR test result.Conclusions:RAA isothermal amplification technology combined with CRISPR-CAS12a technology was used to establish an accurate method for the detection of VZV virus, which was highly sensitive, specific, and had low requirements for experimental conditions, and could be completed within 45 min, which could provide strong technical support for the early detection of VZV.
3.Study on the temporal expression of growth differentiation factor-15 and its mortality prognostic implications in patients with acute coronary syndrome
Bo PAN ; Weiyi MA ; Meng WANG ; Yanfen CHAI ; Songtao SHOU ; Xianfa LIU ; Yanhong OUYANG ; Jingjing HUANG ; Xinhuan DING ; Maolin XU ; Yawen PENG ; Haiyan ZHU
Chinese Journal of Emergency Medicine 2025;34(8):1098-1105
Objective:To investigate the temporal expression of Growth Differentiation Factor-15 (GDF15) in the serum of patients with Acute Coronary Syndrome (ACS) and explore the clinical significance of GDF15 in protecting cardiomyocytes in ACS.Methods:A retrospective study was conducted on 289 ACS patients admitted to the emergency departments from February to October 2023. Data on gender, age, troponin T (TnT), creatine kinase isoenzyme (CK-MB), GDF15, and B-type natriuretic peptide (BNP) within 30 minutes of admission were recorded. Differences in these indicators among different groups were compared. Receiver Operating Characteristic (ROC) curves were plotted to evaluate the diagnostic value of GDF15, TnT, and BNP for ACS. Among the patients, 15 exhibited a temporal expression pattern of GDF15, and their blood samples were re-measured using a GDF15 fluorescent quantitative immunochromatographic assay kit. Fifteen patients without temporal expression were randomly selected as controls, and their samples were also re-measured to exclude detection errors. Fifteen patients with temporal expression were included in the temporal expression group, and 15 without temporal expression were included in the non-temporal expression group. Laboratory indicators such as fasting blood glucose, glycated hemoglobin, triglycerides, creatinine, and uric acid were compared between the groups. Additionally, patient age, gender, body mass index (BMI), coronary angiography results, echocardiography, Gensini score, left ventricular ejection fraction (LVEF), and GRACE risk score were recorded to assess their correlation with GDF15 temporal expression. Statistical analysis was performed using SPSS 27 software, with continuous data expressed as mean ± standard deviation (Mean ± SD) and compared using t-tests and χ2 tests. Results:The overall trend in ACS patients showed a higher proportion of males than females (73.36% vs. 26.64%). The oldest group was the Unstable Angina (UA) group, with a mean age of (63.98 ± 15.19) years, while the youngest group was the non-ACS chest pain group, with a mean age of (54.29 ± 16.39) years. A higher proportion of patients in the UA, ST-segment elevation myocardial infarction (STEMI), and non-ST-segment elevation myocardial infarction (NSTEMI) groups had a history of smoking. The combination of GDF15 and TnT showed high diagnostic value for ACS, with an area under the ROC curve (AUC) of 0.843, consistent with previous studies. Among all ACS patients, 15 exhibited a temporal expression pattern of GDF15, where GDF15 levels peaked at 4 hours, gradually decreased, and peaked again at 24 hours. Patients in the temporal expression group had higher LVEF and left ventricular end-systolic diameter compared to the non-temporal expression group. The Gensini score was lower in the temporal expression group, and the GRACE risk score was significantly lower in the temporal expression group (00.7±14.72) compared to the non-temporal expression group (116.1±23.46), with a statistically significant difference ( P = 0.0115). There were no significant differences in general characteristics (age, gender, BMI) or clinical biochemical indicators (fasting blood glucose, glycated hemoglobin, triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, creatinine, uric acid) between the temporal and non-temporal expression groups ( P > 0.05). Conclusions:GDF15 demonstrates significant diagnostic and prognostic predictive value in ACS. Patients with temporally dynamic expression of serum GDF15 exhibit milder myocardial injury and a lower probability of mortality. These findings provide novel therapeutic targets and research directions for further exploring the role of GDF15 in ACS management.
4.Application value of pulse oximetry in condition assessment of patients with sepsis: a prospective descriptive study
Chen LI ; Yuxin DONG ; Yali NIU ; Youran WANG ; Jun XU ; Xuezhong YU ; Songtao SHOU ; Yanfen CHAI
Chinese Journal of Emergency Medicine 2025;34(10):1390-1395
Objective:To evaluate the utility of pulse oximetry-derived parameters—specifically, the pulse oximetry plethysmographic waveform area under the curve (POP AUC) and the peripheral perfusion index (PPI)—in assessing disease severity and predicting prognosis in patients with sepsis. Methods:In this prospective descriptive study, 68 patients with sepsis were categorized based on illness severity into septic shock and non-shock groups, and by 28-day outcome into survival and non-survival groups. POP AUC, PPI, and lactate (Lac) levels were recorded at 0, 24, 48, 72, and 96 hours after admission. APACHEⅡ and SOFA scores were calculated within the first 24 hours. The prognostic value of these parameters was evaluated. Results:Significant differences were observed between the septic shock and non-shock groups in POP AUC, PPI, Lac (all P < 0.05 except at 96 h), APACHEⅡ, and SOFA scores (all P < 0.05). These differences were most pronounced at admission: POP AUC0 (2475.1 ± 899.0) vs. (4260.3 ± 1028.5), PPI 0 (0.78 ± 0.74) vs. (3.13 ± 2.18), Lac 0 (4.95 ± 4.32) vs. (2.07 ± 1.55), APACHE Ⅱ (16.78 ± 5.59) vs. 11.82 ± 4.89), and SOFA (8.89 ± 3.25) vs. (5.06 ± 2.60). Optimal prognostic cut-off values were 2741.43 for POP AUC, 0.97 for PPI, 2.05 for Lac, 12.5 for APACHEⅡ, and 5.5 for SOFA. ROC curve analysis showed that at 24 hours, POP AUC and PPI had significantly larger AUC values than Lac ( P < 0.05), while no significant differences were found among other parameters. Significant differences between non-survivors and survivors were also found in POP AUC, PPI (at 0, 24, and 48 h), APACHE II, and SOFA (all P < 0.05). No significant differences were observed in PPI (72 h and 96 h) or Lac between the two outcome groups. Conclusions:POP AUC and PPI, as derived from pulse oximetry, are non-inferior to Lac, SOFA, and APACHEⅡ scores in evaluating disease severity and predicting 28-day mortality in sepsis patients. These parameters show promise as practical and non-invasive tools for clinical assessment in sepsis.
5.Glutamate Acid Chemical Exchange Saturation Transfer Imaging in Hippocampus of Depressed Rats Based on 7T Magnetic Resonance Imaging
Linxuan ZHANG ; Songtao WANG ; Kai QI ; Chang XU ; Yingxin LIU ; Wei ZHANG
Chinese Journal of Medical Imaging 2025;33(5):507-511
Purpose Chemical exchange saturation transfer(CEST)imaging is used to study the changes of glutamate metabolism in the hippocampus of rats with chronic unpredictable mild stress(CUMS)model,so as to evaluate the clinical reference value of glutamate acid CEST(GluCEST)imaging results.Materials and Methods Twenty-two male SD rats were enrolled,and were divided into CUMS and healthy groups.Rats in CUMS group were further divided into the non-treatment group(n=7)and the ketamine treatment group(n=8).Seven healthy rats were randomly selected as control group.CEST imaging scans were performed using 7T small animal magnetic resonance and glutamate concentrations were measured in both hippocampi.The difference of hippocampal GluCEST value and glutamate concentration between control group and CUMS non-treatment group,CUMS ketamine treatment group and CUMS non-treatment group was analyzed,respectively.Results Compared with the control group,the hippocampal GluCEST value in CUMS non-treatment group was increased(left:t=2.8,P=0.015;right:t=3.0,P=0.011),while the hippocampal GluCEST value of rats in CUMS ketamine treatment group was decreased compared with CUMS non-treatment group(left:t=2.3,P=0.037;right:t=2.5,P=0.028).Conclusion GluCEST imaging can provide high spatial resolution images and accurately evaluate the changes of glutamate metabolism in hippocampus of rats with depression,which is conducive to monitoring the abnormal signals of hippocampal neurons caused by depression.
6.Determination of Nirmatrelvir in Mouse Plasma Based on the UPLC-MS/MS Method
Songtao HUANG ; Zhifa XIA ; Zhenwei SHI ; Xuan HU ; Shusen YAO ; Qiong WU ; Fenghua XU
Herald of Medicine 2025;44(7):1035-1039
Objective To develop an ultra-high performance liquid chromatography-mass spectrometry method(UPLC-MS/MS)for the determination of nirmatrelvir concentration in mouse plasma.Methods The ACQUITY UPLC system was used in tandem with an API 4000 triple quadrupole mass spectrometer.The analytical column was Waters BEH C18(2.1 mm×5.0 mm,1.7 μm)column,and the mobile phases consisted of water(containing 0.1%formic acid)and methanol(containing 0.1%formic acid)under gradient elution at the flow rate of 0.4 mL·min-1.The column temperature was set at 40 ℃,and the injection volume was 5 μL.Electrospray ionization was used as ion source,and positive multiple reaction monitoring mode was adopted to quantitatively analyze the ionization pairs m/z 500.3→110.3(nirmatrelvir)and m/z 237.3→193.3(carbamazepine).Carbamazepine was employed as an internal standard.Results The linear range of nirmatrelvir was from 10 ng·mL-1 to 2 560 ng·mL-1.For the quality control nirmatrelvir samples,the accuracies of intra-and inter-batch were less than±15%,and the precisions of intra-and inter-batch were lower than 15%.Nirmatrelvir in plasma was stable at room temperature for 24 h and remained stable after three freeze-thaw cycles.The extracted nirmatrelvir solution could be stored at 4℃ for 3 d without any visible change.Conclusion The method was characterized by good specificity,high sensitivity,and appropriate linear range.The methodological validation was in accordance with the 2020 edition of the Chinese Pharmacopoeia and could be applied to the quantitative detection of nirmatrelvir in plasma.
7.Combination of the LPS/TLR4 Pathway and Fecal Metabolomics Analysis Reveals the Chronic Inflammatory Mechanism of Early Atherosclerosis in Tibetan Miniature Pigs
Qinqin YANG ; Songtao XU ; Yueqin CAI ; Yongming PAN ; Junjie HUANG ; Keyan ZHU ; Minli CHEN ; Xiaoping XU
Cardiology Discovery 2025;05(2):121-132
Objective::This study aimed to elucidate the effect of the lipopolysaccharides/toll-like receptor 4 (LPS/TLR4) pathway on early atherosclerosis (AS) development and its associated changes in fecal metabolites, thereby providing an experimental foundation for strategies to prevent and treat early AS.Methods::Twelve Tibetan miniature pigs aged 4-5 months were divided into normal control (NC) group and AS group (6 pigs in each). The group assignment was primarily based on body weight; Secondary criteria, including glucose, lipid profiles, and inflammatory indices, were considered to ensure balanced baseline characteristics between the 2 groups (all P > 0.05). AS group received a high-fat diet for 16 weeks to establish an AS model, while the NC group received a normal diet. Subsequently, serum levels of lipids and various inflammation and oxidative stress markers were measured. Pathological changes in the aorta and colon tissue, LPS/TLR4 pathway-associated protein expressions in the aorta, as well as occludin and zonula occludens-1 in the colon were also assessed. Proton nuclear magnetic resonance spectra technology was employed for the metabolomic analysis of fecal extracts. Results::The lipid metabolism was disrupted in AS group, with significantly higher total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels ((12.24 ± 5.24) mmol/L vs. (1.86 ± 0.27) mmol/L, P = 0.004,6; (2.39 ± 0.50) mmol/L vs. (0.83 ± 0.07) mmol/L, P = 0.000,5; (6.94 ± 2.87) mmol/L vs. (0.77 ± 0.18) mmol/L, P = 0.003,3), as compared to that in NC group. Serum factors, including LPS, tumor necrosis factor-α, and malondialdehyde levels of AS group were significantly higher than that of NC group ((1,230.00 ± 192.70) EU/L vs. (695.70 ± 213.70) EU/L), P = 0.001,1; (424.20 ± 176.90) ng/L vs. (51.20 ± 26.61) ng/L, P = 0.023,5; (3.60 ± 0.77) nmol/mL vs. (2.62 ± 0.21) nmol/mL, P = 0.025,4). Pathological evaluations revealed prominent lipid deposition area in the aortic arch, thoracic aorta, and abdominal aorta of the AS group compared with that of the NC group (4.17% ± 2.30% vs. 0, P = 0.006,7; 6.23% ± 2.95% vs. 0, P = 0.003,6; 3.78% ± 2.18% vs. 0, P = 0.008,1). TLR4, nuclear factor kappa-B p65, and tumor necrosis factor-α expression in the aorta tissue of the AS group were upregulated, whereas occludin and zonula occludens-1 expression in colon tissues was downregulated. Additionally, metabolomics identified significant differences in 21 metabolites in the feces of the AS group compared to the NC group, with further analysis linking these differences to amino acid metabolism. Conclusions::The Tibetan miniature pig model of early AS induced by high-fat intake displayed pronounced chronic inflammation. Preliminary findings suggest that the underlying mechanisms may be associated with the LPS/TLR4 pathway and intestinal metabolic disorders.
8.Combination of the LPS/TLR4 Pathway and Fecal Metabolomics Analysis Reveals the Chronic Inflammatory Mechanism of Early Atherosclerosis in Tibetan Miniature Pigs
Qinqin YANG ; Songtao XU ; Yueqin CAI ; Yongming PAN ; Junjie HUANG ; Keyan ZHU ; Minli CHEN ; Xiaoping XU
Cardiology Discovery 2025;05(2):121-132
Objective::This study aimed to elucidate the effect of the lipopolysaccharides/toll-like receptor 4 (LPS/TLR4) pathway on early atherosclerosis (AS) development and its associated changes in fecal metabolites, thereby providing an experimental foundation for strategies to prevent and treat early AS.Methods::Twelve Tibetan miniature pigs aged 4-5 months were divided into normal control (NC) group and AS group (6 pigs in each). The group assignment was primarily based on body weight; Secondary criteria, including glucose, lipid profiles, and inflammatory indices, were considered to ensure balanced baseline characteristics between the 2 groups (all P > 0.05). AS group received a high-fat diet for 16 weeks to establish an AS model, while the NC group received a normal diet. Subsequently, serum levels of lipids and various inflammation and oxidative stress markers were measured. Pathological changes in the aorta and colon tissue, LPS/TLR4 pathway-associated protein expressions in the aorta, as well as occludin and zonula occludens-1 in the colon were also assessed. Proton nuclear magnetic resonance spectra technology was employed for the metabolomic analysis of fecal extracts. Results::The lipid metabolism was disrupted in AS group, with significantly higher total cholesterol, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol levels ((12.24 ± 5.24) mmol/L vs. (1.86 ± 0.27) mmol/L, P = 0.004,6; (2.39 ± 0.50) mmol/L vs. (0.83 ± 0.07) mmol/L, P = 0.000,5; (6.94 ± 2.87) mmol/L vs. (0.77 ± 0.18) mmol/L, P = 0.003,3), as compared to that in NC group. Serum factors, including LPS, tumor necrosis factor-α, and malondialdehyde levels of AS group were significantly higher than that of NC group ((1,230.00 ± 192.70) EU/L vs. (695.70 ± 213.70) EU/L), P = 0.001,1; (424.20 ± 176.90) ng/L vs. (51.20 ± 26.61) ng/L, P = 0.023,5; (3.60 ± 0.77) nmol/mL vs. (2.62 ± 0.21) nmol/mL, P = 0.025,4). Pathological evaluations revealed prominent lipid deposition area in the aortic arch, thoracic aorta, and abdominal aorta of the AS group compared with that of the NC group (4.17% ± 2.30% vs. 0, P = 0.006,7; 6.23% ± 2.95% vs. 0, P = 0.003,6; 3.78% ± 2.18% vs. 0, P = 0.008,1). TLR4, nuclear factor kappa-B p65, and tumor necrosis factor-α expression in the aorta tissue of the AS group were upregulated, whereas occludin and zonula occludens-1 expression in colon tissues was downregulated. Additionally, metabolomics identified significant differences in 21 metabolites in the feces of the AS group compared to the NC group, with further analysis linking these differences to amino acid metabolism. Conclusions::The Tibetan miniature pig model of early AS induced by high-fat intake displayed pronounced chronic inflammation. Preliminary findings suggest that the underlying mechanisms may be associated with the LPS/TLR4 pathway and intestinal metabolic disorders.
9.Determination of Nirmatrelvir in Mouse Plasma Based on the UPLC-MS/MS Method
Songtao HUANG ; Zhifa XIA ; Zhenwei SHI ; Xuan HU ; Shusen YAO ; Qiong WU ; Fenghua XU
Herald of Medicine 2025;44(7):1035-1039
Objective To develop an ultra-high performance liquid chromatography-mass spectrometry method(UPLC-MS/MS)for the determination of nirmatrelvir concentration in mouse plasma.Methods The ACQUITY UPLC system was used in tandem with an API 4000 triple quadrupole mass spectrometer.The analytical column was Waters BEH C18(2.1 mm×5.0 mm,1.7 μm)column,and the mobile phases consisted of water(containing 0.1%formic acid)and methanol(containing 0.1%formic acid)under gradient elution at the flow rate of 0.4 mL·min-1.The column temperature was set at 40 ℃,and the injection volume was 5 μL.Electrospray ionization was used as ion source,and positive multiple reaction monitoring mode was adopted to quantitatively analyze the ionization pairs m/z 500.3→110.3(nirmatrelvir)and m/z 237.3→193.3(carbamazepine).Carbamazepine was employed as an internal standard.Results The linear range of nirmatrelvir was from 10 ng·mL-1 to 2 560 ng·mL-1.For the quality control nirmatrelvir samples,the accuracies of intra-and inter-batch were less than±15%,and the precisions of intra-and inter-batch were lower than 15%.Nirmatrelvir in plasma was stable at room temperature for 24 h and remained stable after three freeze-thaw cycles.The extracted nirmatrelvir solution could be stored at 4℃ for 3 d without any visible change.Conclusion The method was characterized by good specificity,high sensitivity,and appropriate linear range.The methodological validation was in accordance with the 2020 edition of the Chinese Pharmacopoeia and could be applied to the quantitative detection of nirmatrelvir in plasma.
10.Glutamate Acid Chemical Exchange Saturation Transfer Imaging in Hippocampus of Depressed Rats Based on 7T Magnetic Resonance Imaging
Linxuan ZHANG ; Songtao WANG ; Kai QI ; Chang XU ; Yingxin LIU ; Wei ZHANG
Chinese Journal of Medical Imaging 2025;33(5):507-511
Purpose Chemical exchange saturation transfer(CEST)imaging is used to study the changes of glutamate metabolism in the hippocampus of rats with chronic unpredictable mild stress(CUMS)model,so as to evaluate the clinical reference value of glutamate acid CEST(GluCEST)imaging results.Materials and Methods Twenty-two male SD rats were enrolled,and were divided into CUMS and healthy groups.Rats in CUMS group were further divided into the non-treatment group(n=7)and the ketamine treatment group(n=8).Seven healthy rats were randomly selected as control group.CEST imaging scans were performed using 7T small animal magnetic resonance and glutamate concentrations were measured in both hippocampi.The difference of hippocampal GluCEST value and glutamate concentration between control group and CUMS non-treatment group,CUMS ketamine treatment group and CUMS non-treatment group was analyzed,respectively.Results Compared with the control group,the hippocampal GluCEST value in CUMS non-treatment group was increased(left:t=2.8,P=0.015;right:t=3.0,P=0.011),while the hippocampal GluCEST value of rats in CUMS ketamine treatment group was decreased compared with CUMS non-treatment group(left:t=2.3,P=0.037;right:t=2.5,P=0.028).Conclusion GluCEST imaging can provide high spatial resolution images and accurately evaluate the changes of glutamate metabolism in hippocampus of rats with depression,which is conducive to monitoring the abnormal signals of hippocampal neurons caused by depression.

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